4-amino-2,5-dimethoxy-N-methylbenzenesulphonamide

Toxicity to microorganisms

Administrative data

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

1990

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: well performed study according to acknowledged standards but without GLP

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1990

Report date:

1990

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

Deviations:

not specified

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

4-amino-2,5-dimethoxy-N-methylbenzenesulphonamide

EC Number:

256-435-3

EC Name:

4-amino-2,5-dimethoxy-N-methylbenzenesulphonamide

Cas Number:

49701-24-8

Molecular formula:

C9H14N2O4S

IUPAC Name:

4-amino-2,5-dimethoxy-N-methylbenzene-1-sulfonamide

Details on test material:

purity:97.8 - 98.0 %

Test solutions

Vehicle:

no

Test organisms

Test organisms (species):

activated sludge, domestic

Details on inoculum:

Origin: Domestic sewage treatment plant in Frankfurt / Main - Sindlingen
Content of suspended solids in the sewage sludge suspension : 3.86 g/L
State of acclimatization : not pre-adapted to the test substance or the reference substance

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Test conditions

Test temperature:

19.1 - 20.3 °C

pH:

7.0 - 7.3

Nominal and measured concentrations:

nominal: 500 mg/L and 1000 mg/L

Details on test conditions:

Incubation vessels: Glasbottles with a diameter of 60 mm and a grounded neck (NS 29), height 170 mm and a total volume of approx. 480 ml. The
bottles contained magnetic stirrer bars and were incubated in a water bath on magnetic stirrers.
Test volume: 200 ml each batch
Temperature control : laboratory thermostat
Aeration rate/test vessel: 45 litres per hour, only during the incubation period
Oxygen measurements: With oxygen electrodes, connected to oximeters
Monitoring: During the measuring periods of 10 minutes without further aeration the oxygen concentrations were measured
Respiration rate: The differences of the O2-concentrations between the measurements at the beginning and the end of the 10-min measuring period without aeration accorded to the corresponding respiration rates
Measurements of the pH: pH-meters

Reference substance (positive control):

yes

Remarks:

3,5-dichlorophenol

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

3 h

Dose descriptor:

other: 2.7 % inhibition

Effect conc.:

1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: respiration inhibition

Effect concentrations 2

Duration:

3 h

Dose descriptor:

other: 15.3% inhibition

Effect conc.:

500 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: respiration inhibition

Results with reference substance (positive control):

see table below

Any other information on results incl. tables

Table 1: Measurements and calculated inhibition

Controls	Respiration activity [ mg O2/ L*h ]	Respiration inhibition [%]	pH value	Tem­perature
Blank 1	57.0	(-8.8%)	7.0	20.3
Blank 2	50.3	(4.0%)	7.0	19.4
Blank 3	50.0	(4.6%)	7.2	19.8
Mean of the blanks	52.4	0%
DCP 5 ppm	39.6	24.4%	7.1	20.0
DCP 20 ppm	15.8	69.8%	7.1	19.4
DCP 30 ppm	14.0	73.8%	7.3	20.2
Test batches	Respiration activity [ mg O2 / L*h ]	Respiration inhibition [%]	pH value	Tem­perature
1000 mg/L	57.0	-8.8	7.1	19.9
1000 mg/L	45.0	14.1	7.0	19.8
Mean	51.0	2.7
500mg/L	46.8	10.7	7.0	19.2
500mg/L	42.0	19.8	7.0	19.1
Mean	44.4	15.3

Blanks:Batches without test substance to determine the respiration activity of the used inoculum,
DCP:reference controls with 3,5-Dichlorophenol to test the sensitivity of the inoculum

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The results of testing the toxicity of Chinonbase-sulfmethylamide in the “Activated sludge: respiration inhibition test” revealed that:
The EC20, EC50 and EC80 of Chinonbase-sulfmethylamide to activated sludge (domestic sewage treatment plant) are > 1000 mg/L.

Executive summary:

The determination of the acute toxicity of the substance to domestic activated sludge was performed according to OECD guideline 209

in concentrations of 500 mg/L and 1000 mg/L. 3,5 -Dichlorophenol was used as reference substance.

No relevant toxicity to bacteria was found.